Process and means for making artificial crowns for teeth



E. M. FREDERI'CKS.

, PROCESS AND MEANS FOR MAKING ARTIFICIAL CROWNS FOR TEETH.

AA AAAAAAA N 5 AN. 99999 0. 1,335,372. I Patented Mar. 30,1920.

E sgENTQR.

. ATTORNEYS.

UNITED STATES PATENT OFFICE.

ENORCI-I M. FREDERICKS, OF CHICAGO, ILLINOIS, ASSIGNOR TO JOY TOOTH COMPANY,

i OF CHICAGO, ILLINOIS, A GOBPORATION"OT ILLINOIS.

PROCESS AND MEANS FOR MAKING ARTIFICIAL CROWNS FOR TEETH.

Specification of Letters l atent.

Patented Mar. 30, 1920.

Application filed January 9, 1920. Serial No. 350,280.

To all whom it may concern;

Be it known that I, Enoorr M. FREDER- ICKS, a citizen of the UnitedStates, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Processes and Means for hlaking Artificial Crowns for Teeth,.of which the following is a specification.

This invention relates to improvements in the process of makingor manufacturing artificial crowns for teeth and in the means used therefor, and it consists in certainvnovel' features, steps or acts employed and performed in carrying out the process or method, and in certain peculiarities of the construction, novel arrangement, combination, and operation of the various parts of the mechanism or device employed as will be hereinafter more fully set forth and specifically claimed.

One of the objects of the invention is to furnish a simple and efficient process or method of making artificial tooth crowns of such construction that they may be readily prepared to accurately fit the backing and solder-base, and in some instances the exposed end of the natural roots, with a minimum amount of grinding or cutting away of the parts of the crowns.

Another object is to furnish a process or method of making tooth crowns each having acavity of such shape that the crown can be secured firmly in place on the backing or solder-base, and in some cases, directly and firmly to the root, and in either case in such a manner that in the event of breakage of the crown, it will be unnecessary to re"- movethe crown post in order to place a new crown thereon.

A further object is to provideya process or method for furnishing the cavity of each crown with an inwardly enlarged opening for the reception of the crown post and for the reception of cement used for. fixing said post in position within the cavity of the crown in such a manner that the removal of the crown from the said post, without breaking the crown, will be an impossibility.

Still another object istofurnish a process or'method and means for; producing tooth crowns'with their cavities and the portions at the outer ends of the cavities soformed as to permit of the escape of excess cement used in securing the crown post in position within the cavity ofthe crown, thfls enabling h earn a be numeracynd-emirates fitted to the backing and solder-base or natural root.

Other objects and advantages of the invention will be disclosed in the following description and explanation.

In the accompanying drawing is shown one form of the device used in carrying out or practising the process or method, in which Figure 1 is a plan View of one half of a pair ofmolding flasks or matricesmounted on a supporting body or frame therefor and showing a pair of templets, one in. elevation and the other partly in section, mounted on a carrying bar therefor and located in said flasks in position for use, said view also illustrating one form of means used for holding said bar and its templets inoperative position.

Fig. 2 is a vertical sectional view of one of the crowns as it appears after it has been subjected to a part of the procedure of the method or process showing the perishable core and a post-encircling.-band located in its cavity. I

Fig. 3 is a similar view of a like part of the crown as it appears after'it has undergone further procedure of the method or process, showing the core removed from its cavity and the crown ready for use. I

Fig. 4 is a greatly enlarged detached plan view of the post encircling metal or platinum band.

Fig. 5- is an enlarged vertical sectional view of a portion of a completed crown 7 showing it mounted on the root of a tooth, said root being shown in section and the mount for, the crown being shown partly in section and partly in elevation, and

Fig. 6 is a plan sectional view taken on line 66 of Fig. 5 as indicated by the arrows;

Corresponding numerals of reference designate like parts throughout the different views of the drawings.

The numeral 10 designates as a whole one half of a two-piece frame or supporting body for a plurality of flasks 11 of a twopart or closed type. This frame orsupportingbody 10 is by preference made of brass and has mounted on its upper surface a plurality of flasks 11 of the same material, which have their cavities formed to produce the kind or shape of teeth desired to be made; p j I Ih WB' Sh n n Fig. 1, only two ofthese flasks as said number will be suflicient for the explanation of my process or invention. In this view of the drawing, it will be observed that the open ends of the flasks 11 are located in the same plane and it will be understood that they project upwardly from the body 10 on which they are mounted, which arrangement is for the purpose of permitting a templet carrying bar 12 to be located on the open ends of the flasks with the templets thereof positioned within the cavities of the flasks, yet spaced from the walls thereof.

- The body 10 is provided at its side or edge opposite the open ends of the flasks with a flange or cleat 13 which is disposed in parallelism with the bar 12 when the'same is in position on the frame and flasks. This cleat or flange is employed in connection with a pair of wedges 14 and 15 inserted between the member 13 and the bar 12 for securely holding the latter in proper position, yet in such a manner that it can be readily released and removed from the flasks.

The upper or cope portions of the flasks 11 and the supporting frame or body therefor are counter-parts of that shown in Fig. 1 and above described, and may be placed so as to coincide with the drag or lower portions of the flasks 11 and the corresponding parts of the frame with each other. Each of the templets comprises a metal rod 16, an enlargement 17 of metal and usually circular in shape, and integral with the rod 16, which rod and enlargement are fixed to the bar 1.2. Each templet also comprises a band 18 of platinum or other suitable metal which 7 is closely but detachably mounted on the-rod 16 near the enlargement 17 and a wooden or perishable core 19 mounted on the rod 16, which core is enlarged toward its inner end and by preference is circular in shape.

In carrying out my method or process the bar 12 carrying the templets, each consisting of the parts 16, .17, 1.8 and 19, and as above enumerated, is placed on the open ends of the flask 11 in about the position shown in Fig. 1 of the drawing. When the parts are in such position, a quantity of plastic material such as porcelain, is placed in each of the lower portions of the flask 11 to fill the same, and the cope or upper portions of the flasks are supplied with a quantity of plastic material such as porcelain, and said cope portions are then placed on the drag or lower portions of the flasks so as to coincide with each other and pressed downwardly thereon, which will permit excess of the plastic material being forced out between the meeting edges of the cope and drag portions of each flask. The parts of the device are securely held in the above stated positions with respect to each other by any suitable means and are placed in an oven and subjected to a temperature ofsuflicient degree-and for a sufficient length of time to dissipate all of the moisture contained by the plastic material.

The molds are then withdrawn from the oven and the wedges 14 and 15 removed. The bars 12 and the templets which they carry are then removed from the flasks thus leaving the tooth crowns designated by the numeral 20 within the flasks, which crowns will retain the bands 18 and the enlarged wooden or perishable cores 19 in the sitions and forms shown inFig. 2 of the drawing. It is also obvious that each of the crowns will be provided at the open end of its cavity with an enlarged cavity21 from which the enlargement 17 of the templet has been removed.

The parts of the flasks are now separated and the crowns 20 removed therefrom when they can have their surfaces properly smoothed or prepared, as the biscuitbaked porcelain, at which stage or state the crowns are now in, is of such conditon to undergo or permit of them being scraped or dressed.

The crowns containing the metal bands 18 and perishable cores 19 are now placed in a suitable oven or subjected to a temperature of suflicient degree and for a length of time to fuse and harden the material, which will cause the destruction and removal of the wooden or perishable cores 19 therefrom, and will harden and shrink the crowns sufliciently to firmly hold the bands 18 in it will be understood has its portion located within the tapered part of the cavity of a corresponding taper and smaller than said cavity but has that portion thereof extended outwardly from the inner end of the band 18 of a size to fit snugly within saidband, as is clearly shown in Figs. 5 and 6 of the drawing, in which views, as well as in Fig. 4, it will be seen thatthe band 18 is pro vided with diametrically disposed grooves or recesses 23 which are located longitudinally with respect to the post 22. r

The recesses 23 in the band coincide with recesses 24: formed in the periphery of the post 22 at proper points to register with the recesses 23 of the band and so as to communicate with the enlargement 21 of the cavity, which enlargement is for the "reception and retention of cement 25 with which said enlargement and "the, tapered cavity is suppliedin the act of applying the crown 20 to the root 26 as shown in Fig- 5 of the drawing.

The root 26 hasformed' therein an opening 27 for the reception of a portion of the crown supporting post 22, which portion is 28 to receive cement or like material inserted in the opening of the root of the tooth. At its end or portion adjacent to the root of the tooth when in position thereon the crown 20 is provided with one or more grooves 29 which extend from the outer surface of the crown inwardly and communicate with the recesses 23 of the band in the crown and are employed for the escape of excess cement.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is 1. The herein described process of manufacturing crowns for teeth, consisting in sustaining within a suitably shaped cavity of a mold or flask and at a distance from the walls of said cavity a templet comprising a metal rod, a perishable core mounted on the rod and having its inner portion larger than its outer portion and a metal band encircling said rod at the outer end of said core; then filling the cavity of the mold or flask with lastic material; then heating the thus filled mold until the moisture in the plastic material has been evaporated; then withdrawing said rod from the flask, core and band; then removing the crown from the flask; and then subjecting the crown and its contents to a temperature and for a length of time suflicient to fuse the plastic material.

2. The herein described process of manufacturing crowns for teeth, consisting in forming plastic material into a suitably shaped tooth crown with an inwardly enlarged cavity and simultaneously locating in the smaller portion of said cavity a hand,

then heating the crown with the band therein until the moisture of the plastic material has been evaporated or dissipated; and then subjecting the crown and the band therein to a temperature and for a length of time sufficient to fuse the plastic material.

3. In a device for manufacturing tooth crowns, the combination with a supporting body comprising a pair of counter-part portions each having elevated from one of its surfaces one-half of a flask provided with a suitably shaped cavity and each having outwardly from the open end of the flask a flange, a bar having a templet comprising an enlargement, a rod centrally extended from said enlargement, a band mounted on the rod against the enlargement and a perishable core mounted on the rod and having its inner portion larger than its outer portion, said bar being adapted for location on the open ends of the flask members and its templet extended into the cavities of said members at a distance from the walls thereof, and means interposed between the bar and said flanges for holding the bar in position.

ENOCH M. FREDERICKS. 

